The research: driving stoned

Research has found that using cannabis slows reaction time and your ability to make decisions. If you’re driving under the influence of cannabis, you're increasing your chances of having a car crash by up to 300%. The risk of both fatal and non-fatal car crashes is increased if you drive after you’ve used cannabis. If you think you drive better when you’re stoned – you’re kidding yourself! Don’t believe it? Check out the research in the paragraph below. Watch this video to learn more.

How driving high affects your driving skills

If you're driving high on weed, research shows your attention span and concentration are affected and you have worse hand-eye coordination than usual. If you think playing sport while stoned might be tricky – try avoiding a pedestrian or another car! Driving simulators have shown that driving stoned means people are worse at steering, following cars and finding their place in the lane, as well as managing their speed.

How much does driving under the influence of marijuana affect my driving?

How badly your driving skills are affected when you use marijuana depends on how much you use, that is, the more you use the more the way you drive is negatively affected. People also process ‘THC’, the main ingredient in marijuana, at different speeds – which means marijuana can stay in your system and affect your driving for five or more hours after your last joint or bong!

Is driving stoned illegal?

The police are really concerned about people who drive under the influence of cannabis, their safety and the safety of other people on the road. They have now introduced mobile roadside drug testing – which means next time you get pulled over for a random breath test, you could find yourself running a plastic swab down your tongue and supplying a saliva sample for drug testing. Roadside drug testing is conducted in every state and territory in Australia and, like the test for drunk driving, the location and timing of the drug tests is not promoted in advance. If you’re caught, you risk fines and losing your licence.

For more in-depth information on driving high on weed, check out our Fast facts on cannabis and driving booklet.

The message is clear: if you’ve smoked cannabis, don’t drive.

If you’d like some more info on how cannabis can affect you, check out our other Marijuana Facts, our YouTube channel, follow us on Facebook, or take part in one of our competitions (with some good cash prizes up for grabs). If you think you or a friend might have a problem with cannabis and need help, check out our Get Help page or call the helpline on 1800 30 40 50. You can also get some more in-depth answers to all your cannabis questions on our factsheets page.

*Please note that the terms ‘marijuana’, ‘cannabis’, ‘weed’ and ‘pot’ are used interchangeably in these fast facts, and all refer to the illegal drug, cannabis, unless otherwise specified.